Education Portal for Students in India

Can we rename table name in SQL?

Rename a table –

1. In Object Explorer, right-click the table you want to rename and choose Design from the shortcut menu.
2. From the View menu, choose Properties,
3. In the field for the Name value in the Properties window, type a new name for the table.
4. To cancel this action, press the ESC key before leaving this field.
5. From the File menu, choose Save table name,

How do you rename a table name in SQL w3schools?

SQL RENAME Table The RENAME TABLE statement is used to change the table name. Syntax: RENAME tableName TO newTableName; We can also use the ALTER TABLE statement to change the table name. Syntax: ALTER tableName RENAME TO newTableName;

How to change table name in SQL using alias?

SQL – Alias Syntax You can rename a table or a column in a database temporarily by giving them another pseudo name. This pseudo name is known as Alias, The use of aliases is to address a specific table or a column in an SQL statement without changing their original name in the database.

How to change name in MySQL?

How to rename a column in MySQL using the ALTER TABLE command – To rename a column in MySQL the following syntax is used: ALTER TABLE table_name RENAME COLUMN old_column_name TO new_column_name; This command is used to change the name of a column to a new column name.

How can I rename a database in SQL?

Use SQL Server Management Studio (SSMS) – Suppose I have a database in the on-prem SQL Server instance. I require the new database name as, To rename a database, select the database, right-click on it, and choose Rename, It allows you to edit the database name. Specify a new name and press Enter. You get the following error message if there is an active connection for the SQL database. The error says the rename process could not lock the database exclusively to perform this database. As stated earlier, we need to put the database into single-user mode to get exclusive access. The following query uses the option – ROLLBACK IMMEDIATE, It kills the existing transactions and initiates the rollback for the incomplete transactions.

Refresh the object explorer in SSMS, and you can see the alter database command modifies the database state into single-user mode. Run the following script in the same session where we put the database into single-user mode.

Refresh SSMS object explorer again, and it reflects the new database name. However, the database is still in the single-user mode. The following script changes the database from single-user mode to multi-user mode. Specify the new database name in the alter database script as shown below.

The database is now renamed successfully and accessible for user connections. The sp_helpfile system stored procedure returns the logical, physical name for the connected database. As shown below, it points to the Import database that was the name before renaming.

How to rename database in MySQL?

How do I rename a MySQL database (change schema name)?

• Well there are 2 methods:
• Method 1: A well-known method for renaming database schema is by dumping the schema using Mysqldump and restoring it in another schema, and then dropping the old schema (if needed).
• From Shell

mysqldump emp > emp.out mysql -e “CREATE DATABASE employees;” mysql employees Although the above method is easy, it is time and space consuming. What if the schema is more than a 100GB? There are methods where you can pipe the above commands together to save on space, however it will not save time. To remedy such situations, there is another quick method to rename schemas, however, some care must be taken while doing it. Method 2: MySQL has a very good feature for renaming tables that even works across different schemas. This rename operation is atomic and no one else can access the table while its being renamed. This takes a short time to complete since changing a table’s name or its schema is only a metadata change. Here is procedural approach at doing the rename: Create the new database schema with the desired name. Rename the tables from old schema to new schema, using MySQL’s “RENAME TABLE” command. Drop the old database schema. If there are views, triggers, functions, stored procedures in the schema, those will need to be recreated too, MySQL’s “RENAME TABLE” fails if there are triggers exists on the tables. To remedy this we can do the following things : 1) Dump the triggers, events and stored routines in a separate file. This done using -E, -R flags (in addition to -t -d which dumps the triggers) to the mysqldump command. Once triggers are dumped, we will need to drop them from the schema, for RENAME TABLE command to work. $ mysqldump

-d -t -R -E > stored_routines_triggers_events.out 2) Generate a list of only “BASE” tables. These can be found using a query on information_schema.TABLES table. mysql> select TABLE_NAME from information_schema.tables where table_schema=’
‘ and TABLE_TYPE=’BASE TABLE’; 3) Dump the views in an out file. Views can be found using a query on the same information_schema.TABLES table. mysql> select TABLE_NAME from information_schema.tables where table_schema=’
‘ and TABLE_TYPE=’VIEW’; $ mysqldump > views.out 4) Drop the triggers on the current tables in the old_schema. mysql> DROP TRIGGER ;,5) Restore the above dump files once all the “Base” tables found in step #2 are renamed. mysql> RENAME TABLE
.table_name TO,table_name;, $ mysql < views.out $ mysql < stored_routines_triggers_events.out Intricacies with above methods : We may need to update the GRANTS for users such that they match the correct schema_name. These could fixed with a simple UPDATE on mysql.columns_priv, mysql.procs_priv, mysql.tables_priv, mysql.db tables updating the old_schema name to new_schema and calling "Flush privileges;". Although "method 2″ seems a bit more complicated than the "method 1″, this is totally scriptable. A simple bash script to carry out the above steps in proper sequence, can help you save space and time while renaming database schemas next time. The Percona Remote DBA team have written a script called "rename_db" that works in the following way : # /tmp/rename_db rename_db To demonstrate the use of this script, used a sample schema "emp", created test triggers, stored routines on that schema. Will try to rename the database schema using the script, which takes some seconds to complete as opposed to time consuming dump/restore method. mysql> show databases; +-+ | Database | +-+ | information_schema | | emp | | mysql | | performance_schema | | test | +-+ # time /tmp/rename_db localhost emp emp_test create database emp_test DEFAULT CHARACTER SET latin1 drop trigger salary_trigger rename table emp._emp_new to emp_test._emp_new rename table emp._emp_new to emp_test._emp_new rename table emp.departments to emp_test.departments rename table emp.dept to emp_test.dept rename table emp.dept_emp to emp_test.dept_emp rename table emp.dept_manager to emp_test.dept_manager rename table emp.emp to emp_test.emp rename table emp.employees to emp_test.employees rename table emp.salaries_temp to emp_test.salaries_temp rename table emp.titles to emp_test.titles loading views loading triggers, routines and events Dropping database emp real 0m0.643s user 0m0.053s sys 0m0.131s mysql> show databases; +-+ | Database | +-+ | information_schema | | emp_test | | mysql | | performance_schema | | test | +-+ As you can see in the above output the database schema “emp” was renamed to “emp_test” in less than a second. Lastly, This is the script from Percona that is used above for “method 2″. #!/bin/bash # Copyright 2013 Percona LLC and/or its affiliates set -e if ; then echo “rename_db ” exit 1 fi db_exists=`mysql -h $1 -e “show databases like ‘$3′” -sss` if ; then echo “ERROR: New database already exists $3” exit 1 fi TIMESTAMP=`date +%s` character_set=`mysql -h $1 -e “show create database $2\G” -sss | grep ^Create | awk -F’CHARACTER SET ‘ ‘ ‘ | awk ‘ ‘` TABLES=`mysql -h $1 -e “select TABLE_NAME from information_schema.tables where table_schema=’$2’ and TABLE_TYPE=’BASE TABLE'” -sss` STATUS=$? if || ; then echo “Error retrieving tables from $2” exit 1 fi echo “create database $3 DEFAULT CHARACTER SET $character_set” mysql -h $1 -e “create database $3 DEFAULT CHARACTER SET $character_set” TRIGGERS=`mysql -h $1 $2 -e “show triggers\G” | grep Trigger: | awk ‘ ‘` VIEWS=`mysql -h $1 -e “select TABLE_NAME from information_schema.tables where table_schema=’$2’ and TABLE_TYPE=’VIEW'” -sss` if ; then mysqldump -h $1 $2 $VIEWS > /tmp/$ _views$,dump fi mysqldump -h $1 $2 -d -t -R -E > /tmp/$ _triggers$,dump for TRIGGER in $TRIGGERS; do echo “drop trigger $TRIGGER” mysql -h $1 $2 -e “drop trigger $TRIGGER” done for TABLE in $TABLES; do echo “rename table $2.$TABLE to $3.$TABLE” mysql -h $1 $2 -e “SET FOREIGN_KEY_CHECKS=0; rename table $2.$TABLE to $3.$TABLE” done if ; then echo “loading views” mysql -h $1 $3 < /tmp/$ _views$,dump fi echo "loading triggers, routines and events" mysql -h $1 $3 < /tmp/$ _triggers$,dump TABLES=`mysql -h $1 -e "select TABLE_NAME from information_schema.tables where table_schema='$2' and TABLE_TYPE='BASE TABLE'" -sss` if ; then echo "Dropping database $2" mysql -h $1 $2 -e "drop database $2" fi if ; then COLUMNS_PRIV=" UPDATE mysql.columns_priv set db='$3' WHERE db='$2';" fi if ; then PROCS_PRIV=" UPDATE mysql.procs_priv set db='$3' WHERE db='$2';" fi if ; then TABLES_PRIV=" UPDATE mysql.tables_priv set db='$3' WHERE db='$2';" fi if ; then DB_PRIV=" UPDATE mysql.db set db='$3' WHERE db='$2';" fi if || || || ; then echo "IF YOU WANT TO RENAME the GRANTS YOU NEED TO RUN ALL OUTPUT BELOW:" if ; then echo "$COLUMNS_PRIV"; fi if ; then echo "$PROCS_PRIV"; fi if ; then echo "$TABLES_PRIV"; fi if ; then echo "$DB_PRIV"; fi echo " flush privileges;" fi

How do I edit a table in MySQL?

8.1.10 MySQL Table Editor – The MySQL Table Editor is a used to create and modify tables. You can add or modify the columns or indexes of a table, change the engine, add foreign keys, or alter the table name. To access the MySQL Table Editor, right-click a table name in the Navigator area of the sidebar with the Schemas secondary tab selected and click,

What is the code to rename table in MySQL?

Syntax. RENAME TABLE table_name TO new_name; Where, table_name is the name of an existing table and new_name is the name to which you need to change.

How to display table name in SQL?

How to show all-tables list in a MySQL database – Let us begin with the most basic syntax. The following query will show all tables in a MySQL database: SHOW TABLES; To see all the tables, you can run this statement from MySQL Command Line Client, MySQL Shell, as well as from any GUI tool that supports SQL—for example, dbForge Studio for MySQL,

How to get table names in SQL script?

How do you find names of all tables in a database is a recent SQL interview question asked to one of my friends. There are many ways to find all table names from any database like MySQL and SQL Server. You can get table names either from INFORMATION_SCHEMA or sys.tables based upon whether you are using MySQL or SQL Server database.

1. This is not a popular question like when to use truncate and delete or correlated vs noncorrelated subquery which you can expect almost all candidates to prepare well but this is quite common if you are working on any database like MySQL.
2. In this SQL tutorial, we will see examples of getting names of all tables from MySQL and the SQL Server database.

In MySQL, there are two ways to find the names of all tables, either by using the ” show” keyword or by query INFORMATION_SCHEMA, In the case of SQL Server or MSSQL, You can either use sys.tables or INFORMATION_SCHEMA to get all table names for a database.

What is table alias in SQL?

SQL Aliases – SQL aliases are used to give a table, or a column in a table, a temporary name. Aliases are often used to make column names more readable. An alias only exists for the duration of that query. An alias is created with the AS keyword.

How to rename existing table in Oracle SQL?

Using ALTER TABLE as a rename command in Oracle – There is an alternative to RENAME TABLE that can also be used to give the required table a new name. It is a statement called ALTER TABLE, and it has the following syntax: ALTER TABLE table_name RENAME TO new_table_name; Please note that you can’t rename multiple tables with a single ALTER TABLE statement.

What is alter table in SQL?

SQL ALTER Keyword

The ALTER TABLE command adds, deletes, or modifies columns in a table.The ALTER TABLE command also adds and deletes various constraints in a table.The following SQL adds an “Email” column to the “Customers” table:

ALTER TABLE CustomersADD Email varchar(255); The following SQL deletes the “Email” column from the “Customers” table: ALTER TABLE CustomersDROP COLUMN Email;

What are the rules for table names in SQL?

With regards to writing good SQL code, there are a number of SQL naming conventions as well as best practices which should be followed. Use all lowercase for column and table names and to separate words with an underscore (“_”). For example, start_date and end_date as column names as opposed to StartingDate and EndingDate, and employees as a table name as opposed to Employees,

This works together with the good SQL style convention of capitalizing statements names, clauses, and other keywords for better code readability: SELECT start_date, end_date FROM campaign; For all SQL code and data, using table, column, variable names, or aliases which conflict with SQL keywords and reserved words should be avoided.

Tables and columns should be given clear, easily understandable and uniquely identifying names. Abbreviations should not be used unless absolutely necessary as required by the maximum length enforced for column and table names – in which case it is likely that a different, more succinct name should be considered.

• While some older style guides suggest it, the general consensus amongst more modern style guides is to avoid table and column names with prefixes or suffixes denoting the data or entity type or are a short abbreviation.
• For example, a table name of employees is preferable to tbl_employees, and a column name like customer_account_tx is ambiguous, as it is unclear whether tx is an abbreviation for “transaction” or designating that this column is a text field.

While not a hard-and-fast rule, many style guides suggest only using singular nouns for table names for clarity; e.g. customer as opposed to customers, There are also a number of conventions which are enforced by the SQL engine. Though these vary somewhat between SQL “flavors”, SQL columns and table names should begin with a letter, not end in an underscore, and should contain only alphanumeric characters.

Is it OK to rename a SQL Server?

Prerequisites – Before you begin the renaming process, review the following information:

• When an instance of SQL Server is part of a SQL Server failover cluster, the computer renaming process differs from a computer that hosts a stand-alone instance. For more information, see Rename a SQL Server Failover Cluster Instance,
• SQL Server doesn’t support renaming computers that are involved in replication, except when you use log shipping with replication. The secondary computer in log shipping can be renamed if the primary computer is permanently lost. For more information, see Log Shipping and Replication (SQL Server),
• When you rename a computer that is configured to use Reporting Services, Reporting Services might not be available after the computer name change. For more information, see Rename a Report Server Computer,
• When you rename a computer that is configured to use database mirroring, you must turn off database mirroring before the renaming operation. Then, re-establish database mirroring with the new computer name. Metadata for database mirroring won’t be updated automatically to reflect the new computer name. Use the following steps to update system metadata.
• Users who connect to SQL Server through a Windows group that uses a hard-coded reference to the computer name might not be able to connect to SQL Server. This can occur after the rename if the Windows group specifies the old computer name. To ensure that such Windows groups have SQL Server connectivity following the renaming operation, update the Windows group to specify the new computer name.

You can connect to SQL Server by using the new computer name after you have restarted SQL Server. To ensure that @@SERVERNAME returns the updated name of the local server instance, you should manually run the following procedure that applies to your scenario. The procedure you use depends on whether you are updating a computer that hosts a default or named instance of SQL Server.


Grady A. Lowry